Abstract：In order to realizing the anti-seismic performance of a variable stiffness rigid pile composite-foundation, aseismic behavior of two kinds of the variable stiffness rigid pile composite foundation was analyzed by ANSYS.A kind of finite element analysis software, and the condition of displacement and internal force distributions were calculated out under the same seismic action.The result shows that the max internal force values of a long pile and of a large diameter pile is much more than that of a short pile and that of a small one.Thusly, the strength of a long pile and of a large diameter pile must be enhanced in aseismic design.By contrast, under the same economic conditions, the aseismic performance of a variable length pile is better than that of a variable diameter pile in a variable stiffness rigid pile composite foundation.

Keyword：variable stiffness rigid pile composite-foundation;finite-element method;time history method;seismic response;anti-seismic performance;ANSYS;